Measurement support device, endoscope system, and processor measuring size of subject using measurement auxiliary light

ABSTRACT

A measurement support device including a head configured to emit measurement auxiliary light, an imaging unit to capture an image of a subject on which a spot is formed by the measurement auxiliary light via an imaging optical system, a measurement unit to measure a position of the spot in the image, and a display control unit to display an indicator figure, and information indicating a trajectory along which the spot moves on the image when an imaging distance of the image is changed, wherein, in a case where an optical axis of the measurement auxiliary light is projected on a plane including an optical axis of the imaging optical system, the head emits the measurement auxiliary light that has an inclination angle, which is not 0 degrees with respect to the optical axis of the imaging optical system, and crosses an angle of view of the imaging optical system.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of PCT InternationalApplication No. PCT/JP2018/008356 filed on Mar. 5, 2018 claimingpriority under 35 U.S.C § 119(a) to Japanese Patent Application No.2017-063544 filed on Mar. 28, 2017. Each of the above applications ishereby expressly incorporated by reference, in their entirety, into thepresent application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a measurement support device, anendoscope system, and a processor (a processor for an endoscope system),and particularly, to a measurement support device, an endoscope system,and a processor that measure a size of a subject using measurementauxiliary light.

2. Description of the Related Art

In the field of measurement devices such as endoscopes, measuring adistance to a subject or calculating the length and/or the size of thesubject is performed. For example, JP2008-122759A discloses that asubject distance is measured by a stereoscopic camera, the size of amark serving as a standard of the size of a subject is calculated on thebasis of the subject distance and the angle of view of an endoscope, andthe mark is displayed together with an image of the subject, and thusthe size of the subject can be known from this mark.

Additionally, JP1995-136101A (JP-H07-136101A) discloses a technique ofobtaining a distance to an observed part (observation target) and thesize of the observed part, using measurement light. In JP1995-136101A(JP-H07-136101A), resolving power in the distance from a distal end ofan endoscope insertion part to the observed part and the position of theobserved part is improved by radiating the measurement light obliquelywith respect to a radiation direction of the illumination light.Additionally, JP1995-136101A (JP-H07-136101A) discloses that a rulerimage is displayed to be superimposed on an acquired image and is usedfor measurement.

SUMMARY OF THE INVENTION

In the above-described JP2008-122759A, two cameras are needed in orderto measure the distance with the stereoscopic camera, and a distal endpart of the endoscope becomes large. Thus, a burden on the subjectbecomes high. Moreover, since the distance measurement is performed andthe size of the mark is calculated on the basis of the measurementresult, the system configuration and processing become complicated.

In the case of endoscopic observation, the subject often hasirregularities. In this case, the imaging optical system does notconfront the subject. For this reason, a measurement indicator is mostlikely to be an indicator of a size at a position where a spot of themeasurement light hits, and becomes inaccurate as an indicator as theindicator goes away from the position of the spot. Therefore, in a casewhere the ruler image is moved to any position and rotated by any angleas in JP1995-136101A (JP-H07-136101A), the measurement indicator islikely to be inaccurate as an indicator. Additionally, in a case wherethe spot of the measurement light is separated from a measurementtarget, it is difficult to know how to operate the endoscope to positionthe spot near the measurement target and to perform measurement swiftly.

In this way, in the related art, it is difficult to perform measurementswiftly and easily.

The invention has been made in view of such circumstances, and an objectthereof is to provide a measurement support device, an endoscope system,and a processor (a processor for an endoscope system) capable ofperforming measurement swiftly and easily.

In order to achieve the above-described object, a measurement supportdevice related to a first aspect of the invention comprises: a headconfigured to emit measurement auxiliary light; an imaging unitconfigured to capture an image of a subject on which a spot is formed bythe measurement auxiliary light via an imaging optical system and animaging element; a measurement unit configured to measure a position ofthe spot in the image; and a display control unit configured to displayan indicator figure, which indicates an actual size of a specific regionin the subject and has a size set according to the position of the spotin the image, and information indicating a trajectory along which thespot moves on the image when an imaging distance of the image ischanged, in the vicinity of the position of the spot in the image of thesubject, in which, in a case where an optical axis of the measurementauxiliary light is projected on a plane including an optical axis of theimaging optical system, the head emits the measurement auxiliary lightthat has an inclination angle, which is not 0 degrees with respect tothe optical axis of the imaging optical system, and crosses an angle ofview of the imaging optical system.

In the first aspect, since the information indicating the movementtrajectory of the spot when the imaging distance is changed isdisplayed, it is easy to move the spot to be in the vicinity of themeasurement target (for example, the specific region such as a tumor) bychanging the imaging distance by operating the head and the imaging unitforward or backward, and the measurement can be swiftly and easilyperformed. In addition, since the indicator figure (marker) having asize set according to the position of the spot is displayed, distancemeasurement is not necessary, the configuration is simple, and theprocessing load is low. Further, since the indicator figure and theinformation indicating the trajectory are displayed in the vicinity ofthe spot (for example, the indicator figure is displayed to be centeredon the position of the spot and the trajectory passing on the spotposition is displayed), the difference between the spot position and theposition of the indicator figure is small and thus the indicator figureis accurate as an indicator, and since the indicator figure is notdisplayed in a wide range (entire image or the like), the processingload is low. In the first aspect and each aspect to be described below,an image of a subject, an indicator figure, and information indicating amovement trajectory of a spot can be displayed on a display device suchas various monitors and displays.

Further, according to the first aspect, the optical axis of themeasurement auxiliary light has the inclination angle, which is not 0degrees with respect to the optical axis of the imaging optical system,and crosses the angle of view of the imaging optical system, in a casewhere the optical axis of the measurement auxiliary light is projectedon the plane including the optical axis of the imaging optical system.Thus, by setting the inclination angle appropriately, the measurementauxiliary light can enter the visual field of the imaging optical systemeven in a case where the observation distance is short. Moreover, sincethe optical axis of the measurement auxiliary light has the inclinationangle that is not 0 degrees with respect to the optical axis of theimaging optical system in a case where the optical axis of themeasurement auxiliary light is projected on the plane including theoptical axis of the imaging optical system, the sensitivity of a changein the position of the spot to a change in the observation distance ishigh, and measurement accuracy is high.

In the first aspect, since the trajectory along which the spot moves onthe image when the imaging distance is changed is uniquely determined inaccordance with a relationship between the optical axis of the imagingoptical system and the optical axis of the measurement auxiliary light,the coordinates of the indicator figure can be obtained for a point onthe trajectory. Since the position of the spot in the image correspondsto the imaging distance, in a case where the spot positions aredifferent, display sizes of the indicator figure in the image aredifferent from each other even when the indicator figure has the sameactual size.

In this manner, with the measurement support device related to the firstaspect, the measurement can be swiftly and easily performed. In thefirst aspect, the display of the indicator figure may be performed inreal time (single time for each frame that a spot image is acquired orfor every plural frames), or may be performed offline. In a case wherethe image on which the spot is formed is acquired, the indicator figureand the information indicating the movement trajectory of the spot canbe displayed through post-processing.

In the measurement support device related to a second aspect, in thefirst aspect, the display control unit may display the informationindicating the trajectory in different aspects between a region wheremeasurement of the specific region by the indicator figure displayed inthe vicinity of the position of the spot is effective and a region wheremeasurement of the specific region by the indicator figure displayed inthe vicinity of the position of the spot is not effective, in thetrajectory. In the measurement support device related to the invention,since the measurement is performed using the imaging optical system,depending on the characteristics of the imaging optical system, forexample, distortion may increase at the peripheral part of the angle ofview, and accurate measurement may be difficult in such a region.Further, there may be a case where the imaging distance is too short andthe indicator figure becomes large and extends beyond the image displayrange, or a case where the imaging distance is too long, the indicatorfigure becomes small, and measurement becomes difficult. In view of suchcircumstances, in the second aspect, the information indicating thetrajectory is displayed in different aspects between a region wheremeasurement of the specific region by the indicator figure is effectiveand a region where measurement of the specific region by the indicatorfigure is not effective, and thus the effectiveness of the measurementin the vicinity of the spot position can be easily determined.

In the measurement support device related to a third aspect, in thesecond aspect, in a case where the position of the spot is within ameasurable region set for the image, the display control unit maydetermine that measurement of the specific region by the indicatorfigure is effective. The third aspect indicates an aspect of adetermination reference of measurement effectiveness, and the“measurable region” can be set to a part of the movement trajectory ofthe spot (a central portion of the angle of view or the like), forexample.

In the measurement support device related to a fourth aspect, in thesecond or third aspect, in a case where the imaging distance of theimage calculated on the basis of the position of the spot is within ameasurable range, the display control unit may determine thatmeasurement of the specific region by the indicator figure is effective.The fourth aspect indicates another aspect of a determination referenceof measurement effectiveness. For example, a relationship between theimaging distance and the spot position is measured in advance byacquiring an image on which a spot is formed while the imaging distanceis changed, and a distance can be calculated by referring to therelationship according to the measured spot position.

In the measurement support device related to a fifth aspect, in any oneof the second to fourth aspects, the display control unit may change atleast one of characters, figures, symbols, or colors used for displayingthe information indicating the trajectory between a case wheremeasurement of the specific region by the indicator figure is effectiveand a case where measurement of the specific region by the indicatorfigure is not effective. According to the fifth aspect, whether themeasurement is effective or not can be easily determined by the changeof the display aspects of the information.

In the measurement support device related to a sixth aspect, in any oneof the second to fifth aspects, in a case where measurement of thespecific region by the indicator figure is not effective at the measuredposition of the spot, the display control unit may output informationfor guiding the position of the spot to a range where measurement of thespecific region by the indicator figure is effective. According to thesixth aspect, in a case where the measurement of the specific region bythe indicator figure is not effective at the measured position of thespot, the information for guiding the position of the spot to a rangewhere the measurement of the specific region by the indicator figure iseffective is output, and thus effective measurement can be swiftly andeasily performed. In the sixth aspect, the output of the information maybe performed by figures, symbols, or colors and changes thereof, orperformed by a sound.

In the measurement support device related to a seventh aspect, in anyone of the second to sixth aspects, the display control unit may displaythe indicator figure in different aspects between a case wheremeasurement of a size of the specific region by the indicator figure iseffective and a case where measurement of a size of the specific regionby the indicator figure is not effective. Depending on thecharacteristics of the imaging optical system, for example, distortionmay increase at the peripheral part of the angle of view, and accuratemeasurement may be difficult in such a region. Further, there may be acase where the imaging distance is too short and the indicator figurebecomes large and extends beyond the image display range, or a casewhere the imaging distance is too long, the indicator figure becomessmall, and measurement becomes difficult. In view of such circumstances,in the seventh aspect, the indicator figure is displayed in differentaspects between a case where measurement of the specific region by theindicator figure is effective and a case where measurement of thespecific region by the indicator figure is not effective, and thus theeffectiveness of the measurement in the vicinity of the spot positioncan be easily determined.

The measurement support device related to an eighth aspect, in any oneof the first to seventh aspects, may further comprise an image recordingunit configured to record the image of the subject on which the spot isformed, in which the display control unit may read the image of thesubject recorded in the image recording unit, and display the indicatorfigure to be superimposed on the read image of the subject. According tothe eighth aspect, by recording the image of the subject on which thespot is formed, in the image recording unit, and displaying theindicator figure to be superimposed on the image of the subject readfrom the image recording unit, post-measurement, that is, the offlinemeasurement can be performed. In this manner, it is possible to shortena time during which the measurement support device is used for thesubject, and to reduce the burden on the subject. In the eighth aspect,by storing the image of the subject and the position of the spot in anassociation manner, it is possible to display the indicator figure to besuperimposed on the image read from the image recording unit. Further,the indicator figure can be displayed by referring to the relationshipbetween the spot position and points constituting the indicator figure.

In the measurement support device related to a ninth aspect, in theeighth aspect, the image recording unit may record the image of thesubject and the indicator figure in an association manner, and thedisplay control unit may read the indicator figure and the image of thesubject which are recorded in the image recording unit, and display theread indicator figure to be superimposed on the read image of thesubject. In the ninth aspect, as “the image of the subject and theindicator figure being in an association manner”, for example, the imageof the subject and points constituting the indicator figure can bestored in an association manner, and thus the indicator figure can beswiftly and easily displayed.

In order to achieve the above-described object, an endoscope systemrelated to a tenth aspect comprises: the measurement support device inany one of the first to ninth aspects; and an endoscope including aninsertion part which is to be inserted into the subject, and has adistal end hard part, a bending part connected to a proximal end side ofthe distal end hard part, and a flexible part connected to a proximalend side of the bending part, and an operating part connected to aproximal end side of the insertion part, in which the head and animaging lens that forms an optical image of the spot on the imagingelement are provided in the distal end hard part. Since the endoscopesystem related to the tenth aspect comprises the measurement supportdevice in any one of the first to ninth aspects, the measurement can beswiftly and easily performed.

In the endoscope system related to an eleventh aspect, in the tenthaspect, the endoscope may comprise an information storage unitconfigured to store information indicating the trajectory. Since themovement trajectory of the spot is determined by the configuration andfeatures of the imaging unit and the head, by storing the informationindicating the movement trajectory of the spot in the informationstorage unit of the endoscope as in the eleventh aspect, it is possibleto cope with various endoscopes as the whole endoscope system.

The endoscope system related to a twelfth aspect, in the tenth oreleventh aspect, may further comprise a display condition setting unitconfigured to set a display condition of the indicator figure. Accordingto the twelfth aspect, the user can perform measurement with desireddisplay conditions.

In order to achieve the above-described object, a processor related to athirteenth aspect is a processor for the endoscope system related to anyone of the tenth to twelfth aspects. The processor comprises themeasurement unit and the display control unit. According to thethirteenth aspect, as in the first aspect, the measurement can beswiftly and easily performed.

The processor related to a fourteenth aspect, in the thirteenth aspect,may further comprise an information acquisition unit configured toacquire information of the endoscope, in which the display control unitmay determine whether measurement of the specific region by thedisplayed indicator figure is effective on the basis of the acquiredinformation. By determining the effectiveness of the measurement on thebasis of the information of the endoscope connected to the processor asin the fourteenth aspect, the processor can cope with variousendoscopes.

As described above, with the measurement support device, the endoscopesystem, and the processor (processor for an endoscope system) accordingto the embodiments of the invention, measurement can be swiftly andeasily performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating an entire configuration of an endoscopesystem according to a first embodiment of the invention.

FIG. 2 is a block diagram illustrating the configuration of theendoscope system according to the first embodiment of the invention.

FIG. 3 is a view illustrating a configuration of a distal-end-side endsurface of a distal end hard part.

FIG. 4 is a view illustrating a configuration of a laser module.

FIG. 5 is a sectional view illustrating a configuration of a laser lightsource module.

FIG. 6 is a view illustrating a relationship between an optical axis ofan imaging optical system, and an optical axis of measurement auxiliarylight.

FIG. 7 is a view illustrating a state where an insertion part of theendoscope is inserted into a subject.

FIG. 8 is a flowchart illustrating processing of a measurement supportmethod.

FIG. 9 is a view illustrating a state where the optical axis of themeasurement auxiliary light crosses an imaging angle of view of theimaging optical system.

FIG. 10 is a view illustrating a state where a spot position is changeddepending on a imaging distance.

FIG. 11 is a view illustrating a relationship between a wavelength and asensitivity of color filters.

FIGS. 12A to 12C are views illustrating procedures of an operation usinga movement trajectory of a spot.

FIG. 13 is a view illustrating a state where coordinates of pointsindicating a circular marker are stored for a plurality of points in amovement trajectory of a spot.

FIG. 14 is a view illustrating a relationship between a spot positionand coordinates of points indicating a circular marker.

FIG. 15 is a view illustrating a state where a spot position andcoordinates of points indicating a circular marker are stored in anassociation manner.

FIG. 16 is a view illustrating an example of a display condition settingscreen.

FIG. 17 is another view illustrating an example of the display conditionsetting screen.

FIG. 18 is still another view illustrating an example of the displaycondition setting screen.

FIG. 19 is a view illustrating an example of a screen on which a markerand a movement trajectory of a spot are displayed.

FIG. 20 is a view illustrating a state where the display aspects of thetrajectory are changed between a measurement effective region and otherregions.

FIGS. 21A and 21B are views for describing a measurement effectiveregion.

FIG. 22 is a view illustrating an example in which endpoints of ameasurement effective region are displayed in a movement trajectory of aspot.

FIGS. 23A to 23C are views illustrating a state where the display aspectof the marker is changed in regions other than the measurement effectiveregion.

FIG. 24 is a view illustrating a state where information for guiding aposition of a spot to a measurement effective region is displayed.

FIG. 25 is a view illustrating an image on which a spot is formed.

FIG. 26 is a view illustrating a state where an image on which a spot isformed is stored.

FIG. 27 is a view illustrating a state where a marker read from an imagerecording unit is displayed to be superimposed on an image of a subject.

FIG. 28 is a view illustrating a state where an image of a subject andcoordinates of points indicating a marker are stored in an associationmanner.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of a measurement support device, an endoscopesystem, and a processor for an endoscope system according to theinvention will be described in detail, referring to the accompanyingdrawings.

First Embodiment

FIG. 1 is an external view illustrating an endoscope system 10(measurement support device, endoscope system, and processor) accordingto a first embodiment, and FIG. 2 is a block diagram illustrating theconfiguration of main parts of the endoscope system 10. As illustratedin FIGS. 1 and 2, the endoscope system 10 includes an endoscope body 100(endoscope), a processor 200 (processor), a light source device 300, anda monitor 400 (display device).

<Configuration of Endoscope Body>

The endoscope body 100 comprises a proximal operating part 102(operating part), and an insertion part 104 (insertion part) provided tobe connected to the proximal operating part 102. An operator (user)grips the proximal operating part 102, and inserts the insertion part104 into the body of a subject to observe the body. The proximaloperating part 102 is provided with a memory 139 (information storageunit), and information indicating a trajectory along which a spot ofmeasurement auxiliary light moves on an image when an imaging distanceof the image is changed is stored in the memory 139. As the memory 139,a non-volatile recording medium (non-temporary recording medium) such asa read only memory (ROM), an electronically erasable and programmableread only memory (EEPROM) can be used. In addition, the proximaloperating part 102 is provided with an air-supply and water-supplybutton BT1, a suction button BT2, and a function button BT3 to whichvarious functions (switching between a normal mode and a measurementmode, and the like) can be assigned. The insertion part 104 isconstituted of a flexible part 112 (flexible part), a bending part 114(bending part), and a distal end hard part 116 (distal end hard part)sequentially from the proximal operating part 102 side. By operating theproximal operating part 102, the bending part 114 can be bent to changethe orientation of the distal end hard part 116 vertically andhorizontally. The distal end hard part 116 is provided with an imagingoptical system 130 (imaging unit), an illumination unit 123, a forcepsport 126, a laser module 500, and the like (refer to FIGS. 1 to 3). Acase in which the memory 139 is provided in the proximal operating part102 is described in FIG. 2, but the memory 139 may be provided in alight guide connector 108 or may be provided in an electrical connector109 which connects the processor 200 and the endoscope body 100 (referto FIG. 1).

<Acquisition of Trajectory Information>

The information indicating a movement trajectory of the spot can beacquired, for example, by imaging a grid chart while changing theimaging distance and measuring a spot position corresponding to theimaging distance. A shape of the trajectory is uniquely determined inaccordance with a relationship between an optical axis L1 of themeasurement auxiliary light and an optical axis L2 of the imagingoptical system 130 (refer to FIGS. 9 and 10). However, in a case wherethere is distortion in the imaging optical system 130, the shape of thetrajectory is distorted depending on the distortion. The information canbe stored in the memory 139 (the information storage unit).

During observation or treatment, visible light, infrared light, or bothcan be radiated from illumination lenses 123A and 123B of theillumination unit 123 by the operation of the operating part 208 (referto FIG. 2). Additionally, washing water is released from a water supplynozzle (not illustrated) by the operation of the air-supply andwater-supply button BT1, so that an imaging lens 132 (imaging lens) ofthe imaging optical system 130 and the illumination lenses 123A and 123Bcan be washed. A pipe line (not illustrated) communicates with theforceps port 126 that opens at the distal end hard part 116, and atreatment tool (not illustrated) for tumor removal or the like isinserted through the pipe line and is appropriately moved forward andbackward so as to perform treatment required for the subject.

As illustrated in FIGS. 1 to 3, the imaging lens 132 is disposed on adistal-end-side end surface 116A of the distal end hard part 116. Acomplementary metal-oxide semiconductor (CMOS) type imaging element 134(imaging element and color imaging element), a driving circuit 136, andan analog front end (AFE) 138 are disposed at the back of the imaginglens 132 so as to output image signals. The imaging element 134 is acolor imaging element, and comprises a plurality of pixels constitutedof a plurality of light receiving elements arranged in a matrix(two-dimensional array) in a specific pattern arrangement (Bayerarrangement, X-Trans (registered trademark) arrangement, honeycombarrangement, or the like). Each pixel of the imaging element 134includes a microlens, a red (R), green (G), or blue (B) color filter,and a photoelectric conversion part (photodiode or the like). Theimaging optical system 130 can generate a color image from pixel signalsof three colors of red, green, and blue, or can generate an image frompixel signals of any one color or two colors among red, green, and blue.

In addition, in the first embodiment, a case where the imaging element134 is a CMOS type imaging element is described. However, the imagingelement 134 may be of charge coupled device (CCD) type.

An image of the subject (a tumor part or a lesion part) or an opticalimage of a spot (to be described below) is formed on a light-receivingsurface (imaging surface) of the imaging element 134 by the imaging lens132, and is converted into electrical signals, and the electricalsignals are output to the processor 200 via a signal cable (notillustrated) and are converted into video signals. Accordingly, anobservation image, a circular marker, a movement trajectory of a spot,and the like are displayed on the monitor 400 connected to the processor200. A touch panel may be provided on the monitor 400 for performing adisplay condition setting operation (refer to FIGS. 16 to 19) to bedescribed below via a screen.

Additionally, the illumination lens 123A (for visible light) and theillumination lens 123B (for infrared light) of the illumination unit 123are provided on the distal-end-side end surface 116A of the distal endhard part 116 so as to be adjacent to the imaging lens 132. An exit endof a light guide 170 to be described below is disposed at the back ofthe illumination lenses 123A and 123B, the light guide 170 is insertedthrough the insertion part 104, the proximal operating part 102, and auniversal cable 106, and an incidence end of the light guide 170 isdisposed within the light guide connector 108.

The distal-end-side end surface 116A is further provided with a laserhead 506 (head) of the laser module 500, and the laser head 506 radiatesspot light (measurement auxiliary light) via a prism 512 (refer to FIG.4). The configuration of the laser module 500 will be described later.In addition, in the first embodiment, as illustrated in FIG. 3, thelaser head 506 is provided separately from the forceps port 126.However, the laser head 506 may be removably inserted through the pipeline (not illustrated) communicating with the forceps port 126 thatopens at the distal end hard part 116. Additionally, the laser head 506may be provided between the imaging lens 132 and the forceps port 126.

<Configuration of Laser Module>

As illustrated in FIGS. 2 and 4, the laser module 500 comprises a laserlight source module 502, an optical fiber 504, and a laser head 506(head). A proximal end side (laser light source module 502 side) of theoptical fiber 504 is covered with a fiber covering 501, a distal endside (a side from which laser light is emitted) thereof is inserted intoand is bonded to a ferrule 508 by an adhesive, and an end surface ispolished. A graded index (GRIN) lens 510 is mounted on a distal end sideof the ferrule 508, and the prism 512 is mounted on a distal end side ofthe GRIN lens 510 so as to form a joined body. The ferrule 508 is amember for holding and connecting the optical fiber 504, and a hole forallowing the optical fiber 504 to be inserted therethrough is made emptyin an axial direction (leftward-rightward direction of FIG. 4) at acentral part of the ferrule. A reinforcing member 507 is providedoutside the ferrule 508 and the fiber covering 501 to protect theoptical fiber 504 or the like. The ferrule 508, the GRIN lens 510, andthe prism 512 are housed in a housing 509 and are integrated with thereinforcing member 507 and the fiber covering 501 to constitute thelaser head 506.

In the laser head 506, for example, one having a diameter of 0.8 mm to1.25 mm can be used as the ferrule 508. A fine-diameter ferrule is morepreferable for miniaturization. By virtue of the above-describedconfiguration, the total diameter of the laser head 506 can be 1.0 mm to1.5 mm.

The laser module 500 configured in this way is mounted in the insertionpart 104. Specifically, as illustrated in FIG. 2, the laser light sourcemodule 502 is provided at the proximal operating part 102, the laserhead 506 is provided at the distal end hard part 116, and the opticalfiber 504 guides the laser light from the laser light source module 502to the laser head 506. In addition, the laser light source module 502may be provided within the light source device 300 so as to guide thelaser light to the distal end hard part 116 with the optical fiber 504.

As illustrated in FIG. 5, the laser light source module 502 is a pigtailtype module (transmitter optical sub-assembly (TOSA)) comprising avisible laser diode (VLD) that is supplied with electrical power from apower source (not illustrated) and emits laser light, and a condensinglens 503 that condenses the laser light emitted from the VLD. The laserlight can be emitted as necessary by the control of the processor 200(CPU 210). By emitting the laser light only in a case where measurementis performed (measurement mode), the endoscope body can be usedsimilarly to a normal endoscope during non-emission of laser light(normal mode).

In the first embodiment, the laser light emitted by the VLD can be redlaser light with a wavelength of 650 nm by a semiconductor laser.However, the wavelength of the laser light in the invention is notlimited to this aspect. The laser light condensed by the condensing lens503 is guided up to the GRIN lens 510 by the optical fiber 504. Theoptical fiber 504 is an optical fiber that propagates the laser light ina single transverse mode, and can form a clear spot with a smalldiameter, so that the size of the subject (measurement target) can beaccurately measured. A relay connector may be provided in the middle ofthe optical fiber 504. In addition, in a case where the size of thediameter or clearness of the spot does not pose a measurement problemdepending on observation conditions such as the type or size of thesubject, an optical fiber that propagates the laser light in amulti-mode may be used as the optical fiber 504. Additionally, as thelight source, a light-emitting diode (LED) may be used instead of thesemiconductor laser, or the semiconductor laser may be used in an LEDlight emission state equal to or less than an oscillation thresholdvalue.

The GRIN lens 510 is a cylindrical graded index type lens (radial type)of which the refractive index is highest on the optical axis anddecreases radially outward, and functions as a collimator that makes thelaser light, which is guided by the optical fiber 504 and enters, into aparallel beam and emits the parallel beam. The spread of the beamemitted from the GRIN lens 510 can be adjusted by adjusting the lengthof the GRIN lens 510, and about λ/4 pitch (λ is the wavelength of thelaser light) or the like may be used to emit the laser light as theparallel beam.

The prism 512 is mounted on a distal end side of the GRIN lens 510. Theprism 512 is an optical member for changing the emission direction ofthe measurement auxiliary light. By changing the emission direction, ina case where the optical axis of the measurement auxiliary light isprojected on a plane including the optical axis of the imaging opticalsystem, the optical axis of the measurement auxiliary light has aninclination angle, which is not 0 degrees with respect to the opticalaxis of the imaging optical system, and the measurement auxiliary lightcrosses the angle of view of the imaging optical system. The prism 512is formed to have a size close to the lens diameter of the GRIN lens510, and a distal end surface thereof is cut obliquely so that the prism512 has an apex angle AL1 according to the above-described inclinationangle. The value of the apex angle AL1 can be set in accordance with theemission direction of the laser light and other conditions.

<Relationship Between Optical Axis of Imaging Optical System and OpticalAxis of Measurement Auxiliary Light>

FIG. 6 is a view illustrating a state where the distal end hard part 116according to the first embodiment is seen from the front (subject side),and is a view corresponding to the configuration of FIG. 3. In the firstembodiment, an optical axis L1 of the measurement auxiliary light and anoptical axis L2 of the imaging optical system are present on the sameplane and intersect each other on the same plane. Hence, in a case wherethe distal end hard part 116 is seen from the front (subject side), asillustrated in FIG. 6, the optical axis L1 appears to pass on theoptical axis L2.

In addition, the relationship between the optical axis L1 of themeasurement auxiliary light and the optical axis L2 of the imagingoptical system in the invention may not be limited to theabove-described aspect in which “the optical axis of the measurementauxiliary light and the optical axis of the imaging optical system arepresent on the same plane and intersect each other on the same plane”,and the optical axis of the measurement auxiliary light may not bepresent on the same plane as the optical axis of the imaging opticalsystem. However, even in such a case, in a case where the optical axisof the measurement auxiliary light is projected on the plane includingthe optical axis of the imaging optical system, the optical axis of themeasurement auxiliary light has the inclination angle, which is not 0degrees with respect to the optical axis of the imaging optical system,and crosses the angle of view of the imaging optical system.

In a case where the measurement using the measurement auxiliary light isperformed, if the optical axis of the measurement auxiliary light isparallel to the optical axis of the imaging optical system (theinclination angle is 0 degrees), the distance up to a point where theoptical axis of the measurement auxiliary light crosses the angle ofview of the imaging optical system becomes long depending on the spacingbetween the optical axes. As a result, a spot cannot be imaged in aclosest distance, and the measurement becomes difficult. Additionally,if the optical axis of the measurement auxiliary light is parallel tothe optical axis of the imaging optical system, there is a case wherethe sensitivity of a spot position change with respect to a change inobservation distance is low and sufficient measurement accuracy is notobtained. In contrast, as in the first embodiment, a configuration “in acase where the optical axis of the measurement auxiliary light isprojected on the plane including the optical axis of the imaging opticalsystem, the optical axis of the measurement auxiliary light has theinclination angle, which is not 0 degrees with respect to the opticalaxis of the imaging optical system, and crosses the angle of view of theimaging optical system” is adopted. With this configuration, themeasurement can be made at an observation distance of a wide range fromthe closest distance to a long distance. Additionally, since thesensitivity of the spot position change with respect to the distancechange is high, the measurement can be made with high accuracy.

<Configuration of Light Source Device>

As illustrated in FIG. 2, the light source device 300 is constituted ofa light source 310 for illumination, a stop 330, a condensing lens 340,a light source control unit 350, and the like, and makes illuminationlight (the visible light or infrared light) incident on the light guide170. The light source 310 comprises a visible light source 310A and aninfrared light source 310B, and is capable of radiating one or both thevisible light and the infrared light. The illuminance of theillumination light by the visible light source 310A and the infraredlight source 310B is controlled by the light source control unit 350,and the illuminance of the illumination light can be lowered or theillumination can be stopped as necessary in a case where a spot isimaged and measured (in the measurement mode).

By coupling the light guide connector 108 (refer to FIG. 1) to the lightsource device 300, the illumination light radiated from the light sourcedevice 300 is transmitted to the illumination lenses 123A and 123B viathe light guide 170 and is radiated to an observation range from theillumination lenses 123A and 123B.

<Configuration of Processor>

Next, the configuration of the processor 200 (a measurement unit and adisplay control unit) will be described with reference to FIG. 2. Theprocessor 200 receives the image signals output from the endoscope body100 via an image input controller 202, and performs required imageprocessing by an image processing unit 204 (the measurement unit, thedisplay control unit, the display condition setting unit, and theinformation acquisition unit) to output the image signals via a videooutput unit 206. Accordingly, an observation image is displayed on themonitor 400 (display device). These kinds of processing are performedunder the control of a central processing unit (CPU) 210. That is, theCPU 210 has functions as the measurement unit, the display control unit,the display condition setting unit, and the information acquisitionunit. In the image processing unit 204, switching and superimpositiondisplay of images displayed on the monitor 400, electronic zoomingprocessing, display of images according to operation modes, extractionof a specific component (for example, a brightness signal) from theimage signals, and the like are performed in addition to imageprocessing, such as white balance adjustment. Additionally, the imageprocessing unit 204 performs measurement of spot positions on theimaging surface of the imaging element 134, calculation of the size (thenumber of pixels) of a marker based on the measured positions, and thelike (will be described below). An image of the subject on which thespot is formed and the like are recorded in an image recording unit 207.A sound processing unit 209 outputs a warning message (sound) at thetime of display condition setting and sound information for guiding thespot position to the measurement effective region, through a speaker209A under the control of the CPU 210 and the image processing unit 204.

Examples of the specific hardware structure of the image processing unit204 include processors (electric circuits) such as a central processingunit (CPU), a field programmable gate array (FPGA), and an applicationspecific integrated circuit (ASIC). The image processing unit 204 may beconstituted of one processor, or may be constituted of a combination ofa plurality of processors. The memory 212 includes a storage element fortemporary storage during various processing and a nonvolatile storageelement (a non-temporary recording medium), and in the measurementprocessing, coordinates of spots and coordinates of points indicatingthe circular marker indicating the actual size of the measurement targetin the subject are stored in the memory 212 in an association manner(will be described below) under the control of the CPU 210 and/or theimage processing unit 204. Additionally, computer-readable codes of theprogram that makes the CPU 210 and/or the image processing unit 204execute a measurement support method to be described below are stored inthe memory 212.

Additionally, the processor 200 comprises the operating part 208. Theoperating part 208 comprises an operation mode setting switch (notillustrated) and the like, and can operate radiation of the visiblelight and/or the infrared light. Additionally, the operating part 208includes devices such as a keyboard and a mouse, which are notillustrated, and the user can input various processing conditions,display conditions, and the like via these devices. The displaycondition setting by the operating part 208 will be described below indetail (refer to FIGS. 16 to 19). The setting of the operation mode maybe performed by assigning operation mode setting functions (switchingbetween the measurement mode and the normal mode and the like) to thefunction button BT3 (refer to FIG. 1) of the proximal operating part 102as described above.

<Observation by Endoscope>

FIG. 7 is a view illustrating a state where the insertion part 104 ofthe endoscope body 100 is inserted into the subject, and illustrates astate where an observation image is acquired for an imaging range IA viathe imaging optical system 130. FIG. 7 illustrates a state where a spotSP0 is formed in the vicinity of a tumor tm (a portion that bulges inblack).

<Flow of Measurement Processing>

Next, the measurement support method for the subject using the endoscopesystem 10 will be described. FIG. 8 is a flowchart illustratingprocessing of the measurement support method.

First, the insertion part 104 of the endoscope body 100 is inserted intothe subject, and the endoscope system 10 is set to a normal observationmode (Step S10). The normal observation mode is a mode in which thesubject is irradiated with the illumination light radiated from thelight source device 300 to acquire an image and the subject is observed.The setting to the normal observation mode may be automaticallyperformed by the processor 200 at the time of the startup of theendoscope system 10 or may be performed in accordance with the operationof the operating part 208 by a user.

In a case where the endoscope system 10 is set to the normal observationmode, the illumination light is radiated to image the subject, and theobtained image is displayed on the monitor 400 (Step S12). As the imageof the subject, a still image may be captured or a moving image may becaptured. During the imaging, it is preferable to switch the type (thevisible light or the infrared light) of the illumination light inaccordance with the type of the subject, the purposes of observation, orthe like. The user moves the insertion part 104 forward or backwardand/or operates to bend the insertion part 104 to direct the distal endhard part 116 to an observation target while viewing an image displayedon the monitor 400 so that the subject to be measured is imaged.

Next, in Step S14, whether or not the normal observation mode shifts toa measurement mode is determined. This determination may be performed onthe basis of the presence or absence of a user's operation via theoperating part 208, or may be performed on the basis of the presence orabsence of a switching command from the processor 200. Additionally, theprocessor 200 may alternately set the normal observation mode and themeasurement mode at constant frame intervals (such as every one frame orevery two frames). In a case where the determination of Step S14 isnegative, the process returns to Step S12 and the imaging in the normalobservation mode is continued, and in a case where the determination ofStep S14 is positive, the process proceeds to Step S16 where switchingto the measurement mode is performed.

The measurement mode is a mode in which the laser light (measurementauxiliary light) is radiated from the laser head 506 to form a spot onthe subject, and a marker for measuring the size (length) of the subjecton the basis of the image of the subject on which the spot is formed isgenerated and displayed. In the measurement mode, information indicatinga trajectory along which the spot moves on the image when the imagingdistance is changed is also displayed. In the first embodiment, the redlaser light is used as the measurement auxiliary light. However, sincemuch of a digestive tract is reddish in an endoscope image, there is acase where the spot is not easily recognized depending on themeasurement conditions. Thus, in the measurement mode, during the imageacquisition and the position measurement of the spot, the illuminationlight is turned off or the illuminance is lowered to such a degree thatthe recognition of the spot is not affected (Step S18), and themeasurement auxiliary light is radiated from the laser head 506 (StepS20). Such control can be performed by the processor 200 and the lightsource control unit 350.

In Step S22, an image of the subject on which the spot is formed withthe measurement auxiliary light is captured. In a case where theobservation distance is within a measurement range, the spot is formedwithin the imaging angle of view of the imaging optical system 130. Aswill be described below in detail, the positions of spots within animage (on the imaging element) are different in accordance with theobservation distance, and the sizes (the numbers of pixels) of markersto be displayed are different in accordance with the positions of thespots.

<Change in Spot Positions according to Observation Distance>

In the first embodiment, in a case where the optical axis L1 of themeasurement auxiliary light is projected on the plane including theoptical axis L2 of the imaging optical system, the optical axis L1 hasthe inclination angle, which is not 0 degrees with respect to theoptical axis L2, and crosses the angle of view of the imaging opticalsystem 130. Hence, the positions of spots in an image (imaging element)are different depending on the distance up to the subject. For example,as illustrated in FIG. 9 (a view illustrating a state where the distalend hard part 116 is seen from a lateral direction within the planeincluding the optical axis L1 and the optical axis L2), it is assumedthat observation is possible in a range R1 of the observation distance.In this case, at a nearest end E1, a distance E2 in the vicinity of thecenter, and a farthest end E3 in the range R1, it can be understood thatthe positions of spots (points where the respective arrows and theoptical axis L1 intersect each other) in imaging ranges (indicated byarrows Q1, Q2, and Q3) at the respective points are different from eachother. In addition, in FIG. 9, the inside of solid lines is the imagingangle of view of the imaging optical system 130, and the inside ofone-dot chain lines is a measurement angle of view. Measurement isperformed at a central portion with a small aberration in the imagingangle of view of the imaging optical system 130. The range R1 and themeasurement angle of view in FIG. 9 correspond to a “range where sizemeasurement of a measurement target by a circular marker is effective inthe captured image” (measurement effective region).

FIG. 10 is a view illustrating a state where the distal end hard part116 is seen from the front similarly to FIG. 6, and is a view virtuallyillustrating a relationship between the optical axis L2 of the imagingoptical system 130, the optical axis L1 of the measurement auxiliarylight, and an imaging range R2 of the imaging element 134. FIG. 10illustrates a case where the optical axes L1 and L2 are present on thesame plane and intersect each other on the plane. In FIG. 10, spotpositions P4, P5, and P6 (corresponding to cases where the observationdistances are in the vicinity of the nearest end, in the vicinity of thecenter, and in the vicinity of the farthest end, respectively) accordingto the observation distance are illustrated.

As illustrated in FIG. 10, it can be understood that the spot positionP4 in a case where the observation distance is in the vicinity of thenearest end and the spot position P6 in a case where the observationdistance is in the vicinity of the farthest end are located opposite toeach other with respect to the optical axis L2 of the imaging opticalsystem 130. Hence, in the first embodiment, the sensitivity of themovement of the spot positions with respect to the change in theobservation distance is high, and the size of subject can be measuredwith high accuracy.

In this way, although the spot positions within the captured image (onthe imaging element 134) are different in accordance with therelationship between the optical axis L2 of the imaging optical system130 and the optical axis L1 of the measurement auxiliary light, and theobservation distance. However, the number of pixels indicating the sameactual size (for example, diameter of 5 mm) increases in a case wherethe observation distance is near, and the number of pixels decreases ina case where the observation distance is far. Hence, as will bedescribed below in detail, coordinates of points indicating a circularmarker can be acquired by storing the position (coordinates) of a spot,and coordinates of points indicating a circular marker indicating anactual size of a measurement target (for example, a specific region suchas a tumor and a lesion) in a subject in an association manner in thememory 139, and referring to the stored information in accordance withthe measured spot positions (coordinates). In the measurementprocessing, the information stored in the memory 139 may be expanded inthe memory 212 and the information expanded in the memory 212 may bereferred to. In the first embodiment, since it is not necessary tomeasure the observation distance itself in a case where the coordinatesof the points indicating the circular marker are acquired, theconfiguration is simple, and the processing load is low.

Referring to the flowchart of FIG. 8, the position measurement of a spot(Step S24) on the imaging surface of the imaging element 134 will bedescribed. The position measurement of the spot in Step S24 is performedby an image generated by pixel signals of pixels in which a color filterof a red (R) color is disposed. Here, a relationship between thewavelength and sensitivity in color filters of respective colors (red,green, and blue) disposed in respective pixels of the imaging element134 is as illustrated in FIG. 11. Additionally, the laser light emittedfrom the laser head 506 is red laser light with a wavelength of 650 nm.That is, the measurement of the spot positions is performed on the basisof the image generated by the image signals of the pixels (R pixels) inwhich a color filter of a red color with the highest sensitivity withrespect to the wavelength of the laser light among red, green, and bluecolor filters is disposed. In this case, the position of the spot can berecognized at high speed by providing a threshold value to the signalintensity of the R pixels of bit map data or raw image format (RAW) dataof the pixel signals to perform binarization and calculating the centerof gravity of a white portion (a pixel having a higher signal intensitythan the threshold value). In addition, in a case a spot is recognizedby an actual image (an image generated by pixel signals of all colors),it is preferable that pixel signals of pixels (G pixels and B pixels) inwhich green and blue color filters are disposed are provided withthreshold values, and only the pixels in which values of the pixelsignals of the G pixels and the B pixels having the bit map data areequal to or smaller than the threshold values are extracted.

In addition, in the measurement mode, as described above, during theimage acquisition (Step S22) and the position measurement (Step S24) ofthe spot, the illumination light is turned off or the illuminance islowered to such a degree that the recognition of the spot is notaffected (Step S18), and the measurement auxiliary light is radiatedfrom the laser head 506 (Step S20). Accordingly, an image with a clearspot can be acquired, the position of the spot can be accuratelymeasured, and a marker having a suitable size can be generated anddisplayed.

In Step S26, the processor 200 (the CPU 210 and the image processingunit 204) acquires coordinates of points indicating a circular markerindicating the actual size of the measurement target in the subject. Asdescribed above, the sizes of markers on the monitor 400 are differentin accordance with the positions of spots within an image (namely, onthe imaging surface of the imaging element 134). Thus, coordinates of aspot, and coordinates of points indicating the circular markerindicating an actual size of the measurement target in the subject arestored in an association manner in the memory 139 (or the information ofthe memory 139 is acquired to be stored in the memory 212). Theprocessor 200 refers to the memory 139 (or the memory 212) in accordancewith the spot position measured in Step S24, and acquires thecoordinates of the points indicating the circular marker. A procedure ofobtaining a relationship between the spot positions and the coordinatesof the points indicating the circular marker will be described below indetail. In addition, in Step S26, the processor 200 also acquiresinformation indicating the movement trajectory of the spot from thememory 139 (or the memory 212).

In Step S28, the observation image, the circular marker, and themovement trajectory of the spot are displayed on the monitor 400 on thebasis of the set display conditions (refer to examples of FIGS. 19, 20,22, 23, and the like). In this case, the circular marker being displayedat a position away from the spot is inaccurate as an indicator, thecircular marker is displayed in the vicinity of the spot (with the spotas a center) in the observation image. Circular markers having differentactual sizes (for example, 3 mm, 5 mm, and the like) may beconcentrically displayed, and other markers (for example, cross markers)may be displayed in addition to the circular markers. In addition, themovement trajectory of the spot is displayed by the processor 200 (theCPU 210 and the image processing unit 204) acquiring the informationstored in the memory 139. At the time of the display, the informationstored in the memory 139 may be expanded in the memory 212, and theprocessor 200 may refer to the memory 212 (the same applies to thecircular marker). As described above, the processor 200 acquires anddisplays the information stored in the endoscope body 100, and thus theprocessor 200 can cope with various endoscope bodies.

The display conditions (the type, number, actual size, and color of themarker, and the like) can be set by the user's operation via theoperating part 208 (display condition setting unit) which will bedescribed below (refer to FIGS. 16 to 18).

<Operation Using Movement Trajectory of Spot>

The operation using the movement trajectory of spots will be described.First, the operator operates the proximal operating part 102 to changethe orientation of the distal end hard part 116 vertically andhorizontally, and finds a lesion by screening (circular observation:Procedure 1). The state of Procedure 1 is illustrated in FIG. 12A. Inthe state of Procedure 1, a spot SP2 and a circular marker M2 (centeredon the spot SP2) are present at a position separated from a tumor tm2,and the circular marker M2 is not effective as a measurement indicator.Then, the operator operates the proximal operating part 102 to changethe orientation of the distal end hard part 116 vertically andhorizontally, and causes the tumor tm2 to be placed on a movementtrajectory T2 of the spot as in FIG. 12B (Procedure 2). Since themovement trajectory T2 indicates a movement trajectory of a spot in acase where the imaging distance is changed, the spot SP2 can be placedon the tumor tm2 by pushing and pulling the insertion part 104 from thestate of Procedure 2. In the first embodiment, since the lower left inFIGS. 12A to 12C is the nearest end side of the imaging distance and theupper right in FIGS. 12A to 12C is the farthest end side, the spot SP2is moved to the nearest end side on the movement trajectory T2 bypulling the insertion part 104 toward the proximal side from the statein FIG. 12B, and the spot SP2 can be placed on the tumor tm2 as in FIG.12C (Procedure 3). Since the circular marker M2 is superimposed on thetumor tm2 by Procedure 3, the operator compares the actual size (forexample, 5 mm) of the circular marker M2 with the tumor tm2 to measurethe size of the tumor tm2 (Procedure 4). Further, a release operation(an operation for instructing recording of an image) is performed on theproximal operating part 102 (or the operating part 208) as necessary,and the image on which the spot Sp2 is formed is recorded in the imagerecording unit 207 (image recording unit) (Procedure 5). As describedbelow in detail, in a case where an image, a spot position, and the likeare recorded in the image recording unit 207, processing such as displayof a circular marker and the like can be performed throughpost-processing (refer to FIGS. 25 to 28).

In this manner, in the first embodiment, since the circular markerhaving a size set according to the position of the spot in the image andthe movement trajectory of the spot are displayed in the vicinity of thespot, the operator can easily grasp how the spot and the circular markermove by the operation of the endoscope, and can swiftly and easilyperform measurement.

In a case where the measurement and recording of the image arecompleted, in Step S30, whether the measurement mode is ended isdetermined. This determination may be performed on the basis of theuser's operation (for example, operation of the button B04 in the screendisplay of FIG. 19) via the operating part 208, or may be performed onthe basis of the presence or absence of a switching command from theprocessor 200. Additionally, similarly to the case of shifting to themeasurement mode, in a case where a certain number of frames haveelapsed, the measurement mode may be automatically ended and may returnto the normal observation mode. In a case where the determination ofStep S30 is negative, the process return to Step S20 and the processingof Step S20 to Step S28 is repeated. In a case where the determinationof Step S30 is positive, the process proceeds to Step S32 where themeasurement auxiliary light is turned off, subsequently the illuminanceof the illumination light is returned to normal illuminance in Step S34,and the mode returns to the normal observation mode (returning to StepS10). In addition, in a case where there is no hindrance in theobservation in the normal observation mode, the measurement auxiliarylight may not be turned off.

As described above, in the endoscope system 10 according to the firstembodiment, since a circular marker having a size set according to theposition of the spot in the image and the movement trajectory of thespot are displayed in the vicinity of the spot, the measurement can beswiftly and easily performed.

<Details of Processing of Measurement Support Method>

Hereinafter, processing of the measurement support method describedabove will be described in detail.

<Storage and Acquisition of Coordinates of Circular Marker>

In the first embodiment, a position of a spot, and coordinates of pointsindicating a circular marker in the imaging surface of the imagingelement 134 are stored in an association manner in the memory 212(storage unit), and coordinates are acquired with reference to thememory 212 in accordance with the measured spot position. Hereinafter,storage of the coordinates will be described.

<Storage of Coordinates of Marker>

In the first embodiment, coordinates of points indicating a circularmarker are stored for a plurality of points in a trajectory along whichthe spot moves on the captured image when the observation distance(imaging distance) is changed. The movement trajectory of the spot inthe captured image in a case where the imaging distance is changed isdetermined depending on the relationship between the optical axis L1 ofthe measurement auxiliary light and the optical axis L2 of the imagingoptical system 130, and is a straight line in the case of therelationship illustrated in FIG. 10, but is distorted in accordance withdistortion in a case where the distortion is present in the imagingoptical system 130.

FIG. 13 is a view illustrating an aspect of the coordinate storage, andillustrates a state where coordinates of points indicating a circularmarker are stored for K points (points P1 to PK; K is an integer of 2 ormore) in a movement trajectory T1 of a spot. The point P1 to the pointPK are a measurement effective region (a solid line portion of themovement trajectory T1; corresponding to the inside of the one-dot chainlines in FIG. 9) in which a size measurement by the circular marker iseffective. The point P1 indicates a spot position in a case where thepoint P1 is the nearest end of the measurement effective region, and thepoint PK indicates a spot position in a case where the point PK is thefarthest end of the measurement effective region. In addition, themovement trajectory T1 in FIG. 13 is virtually illustrated.

In a case where the spot is present in a dotted line portion of themovement trajectory T1 (the peripheral portion of the captured image),the distortion becomes large. In addition, there are problems in that apart of the circular marker is out of the image in a case where the spotis present on the nearest end side (a portion of a region T1N indicatedby a dotted line) of the movement trajectory T1, or the marker becomessmall in a case where the spot is present on the farthest end side (aportion of a region T1F indicated by a dotted line), and any of thesecases is not suitable for measurement. Thus, in the first embodiment,coordinates are stored in correspondence with the range of the spotposition (a portion of a region T1E indicated by a solid line) where thesize measurement of the measurement target by the circular marker iseffective.

FIG. 14 is a view illustrating a relationship between a spot positionand coordinates of points indicating a circular marker, and illustratesthe circular marker with L points (points Pi1, Pi2, . . . , Pij, . . . ,PiL; L is an integer) centering on a point Pi (the position of a spot).The value of L can be determined on the basis of the required shapeaccuracy of the marker, and an accurate marker can be displayed as thenumber of points increases. The L points may be connected to each otherby a straight line or a curved line. Additionally, FIG. 15 is a viewillustrating a state where the spot position and the coordinates of thepoints indicating the circular marker are stored in an associationmanner.

<Acquisition of Coordinates>

In a case where the circular marker is displayed, the processor 200 (theCPU 210 and the image processing unit 204) acquires coordinates of thepoints indicating the circular marker with reference to the memory 212(storage unit) on the basis of the measured coordinates of the spot. The“acquisition” herein includes using the stored coordinates and using thecoordinates generated on the basis of the stored coordinates.

The coordinates of the L points indicating the circular marker asillustrated in FIG. 14 are stored for each of the K points (spotpositions) which are the points P1 to PK illustrated in FIG. 13. Forexample, coordinates of the points Pi1 to PiL are stored for the pointPi on the movement trajectory T1. Specifically, as illustrated in FIG.15, the spot positions and the coordinates of the points indicating thecircular marker are stored in an association manner in the memory 212.In this case, the coordinates may be stored to correspond to each of theplurality of actual sizes (for example, 2 mm, 3 mm, 5 mm, 7 mm, and 10mm), and the actual size of the displayed circular marker may beswitched in accordance with the measurement purpose. As the number ofspot positions (K in the examples of FIGS. 13 to 15) of which thecoordinates are stored, and the number of points indicating the circularmarker (L in the examples of FIGS. 13 to 15) increase, the circularmarker can be more accurately displayed.

The coordinates of the points indicating the circular marker may bestored for some points (for example, K points of the points P1 to PK inthe example of FIG. 13) on the movement trajectory T1. In this case, forthe point (spot position) of which the coordinates are not stored, it ispossible to acquire the coordinates of the marker by an aspect (firstaspect) in which the coordinates stored for the points of which thedistance from the measured spot position is within a threshold value areused. In addition, coordinates of the marker can be acquired by anaspect (second aspect) in which coordinates are acquired byinterpolating the coordinates corresponding to two or more points thatsandwich the measured spot, an aspect (third aspect) in whichcoordinates are acquired by extrapolating the coordinates correspondingto two or more points that do not sandwich the measured spot, and thelike.

Meanwhile, coordinates may be stored for all points (pixels) on themovement trajectory T1, and the stored coordinates may be acquired asthey are. In the case of using such aspects, distance calculation,interpolation calculation, and the like between the points can beomitted.

<Generation of Coordinates>

Coordinates of points (the points Pi1 to PiL in the example of FIG. 14)indicating the circular marker can be generated by the following method,for example. Specifically, a square grid chart is imaged while theimaging distance is changed. In this case, the proximal operating partis operated to position the spot at an intersection of the grid, andcoordinates of four points on the top, bottom, right, and left side ofthe spot are measured. Coordinates of other points are generated byinterpolating the measured coordinates of the point. In the chart to beimaged, it is preferable that the interval of the grid is equal to orsmaller than the actual size, and the interval is as fine as possible.Additionally, in order to position the “four points on the top, bottom,right, and left side of the spot” described above at intersections ofthe grid, in the chart to be imaged, it is preferable that the intervalof the grid is an interval (1/integer) of a desired actual size (in acase where the actual size of the circular marker has a diameter of 5mm, the interval of the grid is 0.5 mm, 1 mm, 1.25 mm, 2.5 mm, or thelike). In addition, coordinates of the points indicating a marker havinganother shape such as a cross may be generated on the basis of themeasured spot position and the four points on the top, bottom, right,and left side of the spot.

<Setting of Screen Display Condition>

The display condition setting such as the captured image, the circularmarker, the movement trajectory of the spot, and the like, and displayaspects depending on the set conditions will be described. FIG. 16 is aview illustrating an example of an entire screen for setting screendisplay conditions. FIG. 16 illustrates condition names (regions C01 toC11), contents of the set condition (numerical value or the like;regions V01 to V11), and buttons A01 to A11 for the condition settingfor items of the screen display conditions. The buttons B01, B02, andB03 provided in a lower portion of the screen are respectively forconfirming the display condition, for canceling the condition change,and for clearing the condition change (returning to initial values). Thescreen of FIG. 16 is displayed on the monitor 400, and the displayconditions can be set by the user's operation via a touch panel of themonitor 400 and/or a keyboard and a mouse (not illustrated) of theoperating part 208. Such display condition setting may be performed atany time during the execution of the flowchart of FIG. 8. The layout andthe display items of the display condition setting screen to bedescribed below are examples of the display condition setting, and otheraspects can be adopted as needed.

The regions C01 and V01 indicate whether a movement trajectory of a spotis displayed, and the display of the movement trajectory can be turnedon or off by a selection operation via the button A01. The regions C02and V02 indicate an aspect of the measurement effective region (displayaspect) in the movement trajectory of the spot, and a solid line, adotted line, or the like can be selected by an operation via the buttonA02. The regions C03 and V03 indicate a color of the measurementeffective region in the movement trajectory of the spot, and a colorsuch as white or blue can be selected by an operation via the buttonA03. The regions C04 and V04 indicate an aspect of the measurementnon-effective region (display aspect) in the movement trajectory of thespot, and a dotted line, a chain line, or the like can be selected by aselection operation via the button A04. The regions C05 and V05 indicatea color of the measurement non-effective region in the movementtrajectory of the spot, and a color such as red or black can be selectedby a selection operation via the button A05. The regions C06 and V06indicate whether information (for example, a triangular figureillustrated in FIG. 24) for guiding the position of the spot to themeasurement effective region is output, and whether the information isoutput (output or no output) can be selected by an operation via thebutton A06. The regions C07 and V07 indicate whether endpoints of themeasurement effective region are displayed, and whether the endpointsare displayed (displayed or not displayed) can be selected by anoperation via the button A07. The regions C08 and V08 indicate whether amarker is displayed, and ON or OFF of the display can be selected by anoperation via the button A08. The regions C09 and V09 indicate a shapeof a marker to be displayed, and an aspect such as a circle or a crosscan be selected by an operation via the button A09. The regions C10 andV10 indicate a color of a marker to be displayed, and a color such aswhite or blue can be selected by an operation via the button A10. Theregions C11 and V11 indicate an actual size of a marker to be displayed,and a size such as 2 mm, 3 mm, or 5 mm can be selected by a selectionoperation via the button A11 (refer to FIG. 18).

<Specific Example of Display Condition Setting>

The specific example of the display condition setting operation will bedescribed. FIG. 17 is a view illustrating an example of a screen forsetting the aspect (display aspect) of the measurement effective regionin the movement trajectory of the spot. In the screen of FIG. 16, in acase where the button A02 is designated by an operation on the touchpanel of the monitor 400 or an operation via the operating part 208 (thesame applies to other items), the region V02 is displayed in a pull-downmanner and transitions to a state of FIG. 17. The illustration for itemsother than the aspect of the measurement effective region in FIG. 17 isomitted. In FIG. 17, conditions (in this case, solid line, dotted line,and one-dot chain line) that can be set as display aspects in themeasurement effective region are displayed in the region V02, and theuser moves a selection range up and down with buttons A02 a and A02 band a slide bar A02 c to select the aspect (for example, solid line) anddetermines the display aspect by designating the button B01 (OK button).

FIG. 18 is a view illustrating an example of a screen for setting anactual size (size) of the marker. In the screen of FIG. 16, in a casewhere the button A11 is designated, the region V11 is displayed in apull-down manner and transitions to a state of FIG. 18 (the illustrationfor items other than the actual size is omitted). In the example of FIG.18, the actual size of the marker can be selected from “2 mm, 3 mm, 5mm, 7 mm, and 10 mm”, and the user moves a selection range up and downwith buttons A11 a and A11 b and a slide bar A11 c to select the actualsize (5 mm in FIG. 18), and designates the button B01. Additionally, theexpression “the actual size of the marker is 5 mm” means that “a markerhaving a size (the number of pixels) corresponding to 5 mm is displayedon the screen of the monitor 400”, and the size of marker on the screenof the monitor 400 does not have to be 5 mm.

In the setting of the display condition described above, in a case wherethe conditions respectively set for the items do not match, a warningmessage may be output via the monitor 400 and/or the speaker 209A.

<Setting of Display Condition by Other Operation Means>

In the above-described example, the case in which the display conditionsof the marker are set by the touch panel of the monitor 400 and/or akeyboard and a mouse (not illustrated) of the operating part 208 hasbeen described. However, the display conditions may be set by otheroperation means. For example, the display condition may be set byassigning a function to the function button BT3 of the proximaloperating part 102. In addition, the display condition may be set by afoot pedal, a voice input, a gaze input, a gesture input, and the like.The user may not be able to freely move both hands during the operationof the endoscope body 100, and in such a case, the operation means iseffective.

<Specific Example of Screen Display>

An example of the screen display with the conditions illustrated in FIG.16 is illustrated in FIG. 19. As illustrated in FIG. 19, the screendisplayed on the monitor 400 is constituted of an image display regionD01 and an information display region D02. In the image display regionD01, a spot SP1 is formed on a tumor tm1, and a circular marker M1(actual size with a diameter of 5 mm) centered on the spot SP1 isdisplayed in white. In addition, the movement trajectory T1 of the spotis displayed, and is displayed in different aspects between a region T1Ewhere measurement by the circular marker M1 is effective and otherregions (a region T1N on the nearest end side and a region T1F on thefarthest end side). Markers M1N and M1F are displayed at endpoints ofthe region T1E.

Meanwhile, in the information display region D02, the fact that theendoscope system 10 is the “measurement mode” is displayed in a regionD02A and current display conditions are displayed in a region D02B. In acase where the button B04 is designated, the mode is changed to thenormal observation mode, and in a case where the button B05 isdesignated, the display condition setting screen as in FIG. 16 isdisplayed.

In the endoscope system 10 according to the first embodiment, thedisplay conditions can be easily checked and changed by theabove-described information display region D02, and thus the measurementcan be swiftly and easily performed. The information display region D02may be a separate screen, and the image display region D01 may bewidened by hiding or reducing the information display region D02 duringthe observation mode.

<Display Aspect of Marker and Movement Trajectory of Spot>

In the invention, the marker (indicator figure) and the movementtrajectory of the spot may be displayed in the following aspects.

<Identification Display of Measurement Effective Region>

FIG. 20 is a view illustrating an example in which display aspects ofthe movement trajectory of the spot are changed between the region wherethe measurement by the marker is effective and the region where themeasurement by the marker is not effective. In FIG. 20, in the movementtrajectory T1, a region T1E where measurement of a tumor tm3 by acircular marker M3 centering on a spot SP3 is effective is illustratedusing a solid line, and a region T1N on the nearest end side and aregion T1F on the farthest end side where the measurement by thecircular maker M3 is not effective are illustrated using dotted lines.That is, in FIG. 20, in a case where a spot is present in the regionT1E, the measurement is effective, and in a case where a spot is presentin the region T1N or the region T1F, the measurement is not effective.The “region where measurement is effective” in the identificationdisplay is a region (corresponding to the range R1 of FIG. 9) which isin the vicinity of the center of the captured image and in which theinfluence of the distortion of the imaging optical system 130 is smalland the marker does not extend beyond the image or become too small. Insuch a region, it is possible to perform accurate measurement. In theidentification display, without being limited to the aspect of using thesolid line and the dotted line, other kinds of a line may be used, andthe thickness of the line, color, a figure and/or a symbol to be used,and the like may be changed.

Whether the measurement by the marker is effective or not can be easilydetermined by the identification display of the measurement effectiveregion as illustrated in FIG. 20 (the display aspects of the movementtrajectory of the spot are changed between a region where measurement bya marker is effective and a region where measurement by a marker is noteffective), and thus the measurement can be swiftly and easilyperformed. Additionally, in addition to the identification display ofthe measurement effective region, the movement trajectory may bedisplayed in different aspects in accordance with the imaging distance.For example, conditions such as kinds of a line, a thickness of a line,a color, a figure, and a symbol may be changed in a region where theimaging distance is close and in a region where the imaging distance isfar.

The above-described “region where measurement by a marker is effective”(measurement effective region) may be set to a part of the image or maybe set for a range of the imaging distance. For example, a grid chart onwhich a spot is formed is imaged while the imaging distance is changed,the size of the grid, the distortion degree of the grid, and the likeare measured at each distance, and the measurement effective region canbe set on the basis of the measurement result. FIG. 21A conceptuallyillustrates a measurable range (D1 to D2) set for the imaging distancein the above-described procedure, and spot positions (X coordinate isfrom X1 to X2) corresponding to the measurable range. Further, FIG. 21Bconceptually illustrates the measurable range (D1 to D2) set for theimaging distance, and spot positions (Y coordinate is from Y1 to Y2)corresponding to the measurable range. In the example of FIGS. 21A and21B, in a case where the X coordinate of the spot positions is from X1to X2 and the Y coordinate thereof is from Y1 to Y2 (an inside of themeasurable region) and in a case where the imaging distance is withinthe measurable range (imaging distance is from D1 to D2), it isdetermined that “measurement by the marker is effective”. Suchinformation of the measurement effective region is stored in the memory139, and the processor 200 (the CPU 210 and the image processing unit204) can acquire such information to determine “whether measurement bythe marker is effective”. By determining the effectiveness of themeasurement on the basis of the information of the endoscope body 100connected to the processor 200 in this manner, the processor 200 cancope with various endoscopes.

<Identification Display of Endpoints of Measurement Effective Region>

FIG. 22 is a view illustrating an example in which endpoints of theregion where measurement by a marker is effective are displayed to beidentified, and displays endpoints of the region T1E where measurementof a tumor tm4 by a circular marker M4 is effective, using markers M4Nand M4F. Whether the measurement by the circular marker M4 is effectiveor not can be easily determined by the identification display of theendpoints, and thus the measurement can be swiftly and easily performed.Further, FIG. 22 illustrates the case where the identification displayof the endpoints is combined with the identification display illustratedin FIG. 20 (in the movement trajectory T1 of the spot, the region T1Ewhere the measurement by the circular marker M3 is effective isdisplayed using a solid line, and the regions T1N and T1F where themeasurement by the circular marker M3 is not effective are displayedusing dotted lines). However, only the endpoints may be displayed to beidentified.

<Display Aspect of Marker according to Effectiveness of Measurement>

FIGS. 23A to 23C are views illustrating an example in which the displayaspects of the marker are changed between a region where measurement bythe marker is effective and other regions. Specifically, in a case wherea spot SP5N is present in a region T1N on the nearest end side of amovement trajectory T1 as illustrated in FIG. 23A and in a case where aspot SP5F is present in a region T1F on the farthest side of themovement trajectory T1 as illustrated in FIG. 23C, since the measurementof a tumor tm5 by circular markers M5N and M5F are not effective, thecircular markers M5N and M5F are respectively displayed using dottedlines. In FIGS. 23A and 23C, the circular markers on the nearest endside and the farthest side are displayed using dotted lines, butdifferent kinds of a line may be used or different colors may be usedfor the circular markers on the nearest end side and the farthest side.Meanwhile, in a case where a spot SP5 is present in a region T1E wherethe measurement by a circular marker M5 is effective as illustrated inFIG. 23B, the circular marker M5 is displayed using a solid line.

Whether the measurement by the marker is effective or not can be easilydetermined by the display aspects of the marker as described above, andthus the measurement can be swiftly and easily performed.

<Guiding to Measurement Effective Region>

In a case where the circular marker is not present in theabove-described measurement effective region, information for guiding tothe measurement effective region may be output. For example, in a casewhere the spot SP5F is present in the region T1F (farthest end side)where the measurement is not effective as illustrated in FIG. 24, afigure G1 indicating an operation direction of the insertion part 104can be displayed. The figure G1 has a triangular shape, the operator(user) can easily grasp that “the circular marker is guided to themeasurement effective region (direction of the tumor tm7) by operatingthe insertion part 104 in the apex direction of the triangle (pullingthe insertion part toward the proximal side)” by the figure G1. Theinformation for guiding to the measurement effective region is notlimited to the figure G1, other symbols such as an arrow can be used asthe information for guiding to the measurement effective region, andcolors or sizes which can be easily identified can be set. An animationin which a figure or the like is dynamically changed may be displayed.In addition, characters or symbols may be used instead of the figure orin addition to the figure. Further, guiding may be performed using asound (for example, “please, push the cope” or “please, pull the scope”)by the sound processing unit 209 and the speaker 209A (refer to FIG. 2)instead of the visual display or in addition to the visual display. Byoutputting such information, guiding to the measurement effective regionbecomes easy, and the measurement can be swiftly and easily performed.

<Offline Processing by Recording Image>

In the endoscope system 10 according to the first embodiment, processingsuch as the marker display or the like and the measurement based on theprocessing may be performed in real time (display of a marker or atrajectory for each time an image on which a spot is formed is acquiredor for every plural frames), or offline processing (post-processing) maybe performed as described below. In order to perform the offlineprocessing, an image on which a spot SP6 is formed on a tumor tm6 as inFIG. 25 is stored in the image recording unit 207. In this case, asillustrated in FIG. 26, the image (image file) and the spot position(coordinates) are recorded in an association manner. As described above,since the spot positions and the coordinates of the points indicatingthe circular marker are stored in an association manner in the memory139 (or the memory 212) (refer to FIG. 15), the coordinates of thepoints indicating the circular marker can be acquired by referring tothe memory 139 (or the memory 212) on the basis of the spot positionsrecorded in association with the image. Hence, by the acquisition of thecoordinates, the circular marker can be displayed to be superimposed onthe image read from the image recording unit 207. FIG. 27 is an exampleof display by the post-processing, and the circular marker M6 centeredon the spot SP6 is displayed to be superimposed on an image of the tumortm6.

In addition to the above-described aspects, the image and the circularmarker may be recorded in an association manner. For example, asillustrated in FIG. 28, an image (image file), a spot position(coordinates), and coordinates of points indicating a circular marker(which can be acquired by referring to the memory 139 or the memory 212)are recorded in an association manner in the image recording unit 207.Accordingly, the recorded image and the recorded coordinates of thepoints indicating the circular marker can be read and the circularmarker can be displayed to be superimposed on the image (refer to FIG.27).

As described above, by recording the captured image, the spot position,the coordinates of the points indicating the circular marker, and thelike in an association manner, the post-processing such as the displayof the circular marker or the like and the measurement can be performed,and thus it is possible to shorten the time during which the endoscopeis inserted into the subject and thus to reduce the burden on thesubject. As the image or the like used for the measurement, not only theimages recorded in the image recording unit 207 may be used, but alsoimages acquired from a non-temporary recording medium such as a compactdisk (CD) or a digital versatile disc (DVD) via the image inputinterface 205 (refer to FIG. 2) may be used.

<Others>

The measurement support device, the endoscope system, and the processoraccording to the embodiments of the invention can also be applied tocases where subjects, which are not living bodies, such as a pipe, aremeasured in addition to measuring the subject that is a living body.Additionally, the measurement support device according to theembodiments of the invention can be applied not only to the endoscopebut also to the cases of measuring the dimensions and shapes of anindustrial part or the like.

Although the embodiments of the invention have been described above, itis obvious that the invention is not limited to the above-describedaspects, and various modifications can be made without departing fromthe spirit of the invention.

EXPLANATION OF REFERENCES

-   -   10: endoscope system    -   100: endoscope body    -   102: proximal operating part    -   104: insertion part    -   106: universal cable    -   108: light guide connector    -   109: electrical connector    -   112: flexible part    -   114: bending part    -   116: distal end hard part    -   116A: distal-end-side end surface    -   123: illumination unit    -   123A: illumination lens    -   123B: illumination lens    -   126: forceps port    -   130: imaging optical system    -   132: imaging lens    -   134: imaging element    -   136: driving circuit    -   138: AFE    -   139: memory    -   170: light guide    -   200: processor    -   202: image input controller    -   204: image processing unit    -   205: image input interface    -   206: video output unit    -   207: image recording unit    -   208: operating part    -   209: sound processing unit    -   209A: speaker    -   210: CPU    -   212: memory    -   300: light source device    -   310: light source    -   310A: visible light source    -   310B: infrared light source    -   330: stop    -   340: condensing lens    -   350: light source control unit    -   400: monitor    -   500: laser module    -   501: fiber covering    -   502: laser light source module    -   503: condensing lens    -   504: optical fiber    -   506: laser head    -   507: reinforcing member    -   508: ferrule    -   509: housing    -   510: GRIN lens    -   512: prism    -   A01: button    -   A02: button    -   A02 a: button    -   A02 c: slide bar    -   A03: button    -   A04: button    -   A05: button    -   A06: button    -   A07: button    -   A08: button    -   A09: button    -   A10: button    -   A11: button    -   A11 a: button    -   A11 c: slide bar    -   AL1: apex angle    -   B01: button    -   B02: button    -   B03: button    -   B04: button    -   B05: button    -   BT1: air-supply and water-supply button    -   BT2: suction button    -   BT3: function button    -   C01: region    -   C02: region    -   C03: region    -   C04: region    -   C05: region    -   C06: region    -   C07: region    -   C08: region    -   C09: region    -   C10: region    -   C11: region    -   D01: image display region    -   D02: information display region    -   D02A: region    -   D02B: region    -   E1: nearest end    -   E2: distance    -   E3: farthest end    -   G1: figure    -   IA: imaging range    -   L1: optical axis    -   L2: optical axis    -   M1: circular marker    -   M1N: marker    -   M2: circular marker    -   M3: circular marker    -   M4: circular marker    -   M4N: marker    -   M5: circular marker    -   M5N: circular marker    -   M6: circular marker    -   P4: spot position    -   P5: spot position    -   P6: spot position    -   Q1: arrow    -   Q2: arrow    -   Q3: arrow    -   R1: range    -   R2: imaging range    -   S10 to S34: respective steps of measurement support method    -   SP0: spot    -   SP1: spot    -   SP2: spot    -   SP3: spot    -   SP5: spot    -   SP5F: spot    -   SP5N: spot    -   SP6: spot    -   T1: movement trajectory    -   T1E: region    -   T1F: region    -   T1N: region    -   T2: movement trajectory    -   V01: region    -   V02: region    -   V03: region    -   V04: region    -   V05: region    -   V06: region    -   V07: region    -   V08: region    -   V09: region    -   V10: region    -   V11: region    -   tm: tumor    -   tm1: tumor    -   tm2: tumor    -   tm3: tumor    -   tm4: tumor    -   tm5: tumor    -   tm6: tumor    -   tm7: tumor

What is claimed is:
 1. A measurement support device comprising: a head configured to emit measurement auxiliary light; an imaging unit configured to capture an image of a subject on which a spot is formed by the measurement auxiliary light via an imaging optical system and an imaging element; a processor configured to function as: a measurement unit configured to measure a position of the spot in the image; and a display control unit configured to display an indicator figure, which indicates an actual size of a specific region in the subject and has a size set according to the position of the spot in the image, and information indicating a trajectory along which the spot moves on the image when an imaging distance of the image is changed, in the vicinity of the position of the spot in the image of the subject, wherein, in a case where an optical axis of the measurement auxiliary light is projected on a plane including an optical axis of the imaging optical system, the head emits the measurement auxiliary light that has an inclination angle, which is not 0 degrees with respect to the optical axis of the imaging optical system, and crosses an angle of view of the imaging optical system.
 2. The measurement support device according to claim 1, wherein the display control unit displays the information indicating the trajectory in different aspects between a region where measurement of the specific region by the indicator figure displayed in the vicinity of the position of the spot is effective and a region where measurement of the specific region by the indicator figure displayed in the vicinity of the position of the spot is not effective, in the trajectory.
 3. The measurement support device according to claim 2, wherein, in a case where the position of the spot is within a measurable region set for the image, the display control unit determines that measurement of the specific region by the indicator figure is effective.
 4. The measurement support device according to claim 2, wherein, in a case where the imaging distance of the image calculated on the basis of the position of the spot is within a measurable range, the display control unit determines that measurement of the specific region by the indicator figure is effective.
 5. The measurement support device according to claim 2, wherein the display control unit changes at least one of characters, figures, symbols, or colors used for displaying the information indicating the trajectory between a case where measurement of the specific region by the indicator figure is effective and a case where measurement of the specific region by the indicator figure is not effective.
 6. The measurement support device according to claim 2, wherein, in a case where measurement of the specific region by the indicator figure is not effective at the measured position of the spot, the display control unit outputs information for guiding the position of the spot to a range where measurement of the specific region by the indicator figure is effective.
 7. The measurement support device according to claim 2, wherein the display control unit displays the indicator figure in different aspects between a case where measurement of a size of the specific region by the indicator figure is effective and a case where measurement of a size of the specific region by the indicator is not effective.
 8. The measurement support device according to claim 1, wherein the processor is further configured to function as: an image recording unit configured to record the image of the subject on which the spot is formed, wherein the display control unit reads the image of the subject recorded in the image recording unit, and displays the indicator figure to be superimposed on the read image of the subject.
 9. The measurement support device according to claim 8, wherein the image recording unit records the image of the subject and the indicator figure in an association manner, and the display control unit reads the indicator figure and the image of the subject which are recorded in the image recording unit, and displays the read indicator figure to be superimposed on the read image of the subject.
 10. An endoscope system comprising: the measurement support device according to claim 1; and an endoscope including an insertion part which is to be inserted into the subject, and has a distal end hard part, a bending part connected to a proximal end side of the distal end hard part, and a flexible part connected to a proximal end side of the bending part, and an operating part connected to a proximal end side of the insertion part, wherein the head and an imaging lens that forms an optical image of the spot on the imaging element are provided in the distal end hard part.
 11. The endoscope system according to claim 10, wherein the endoscope includes an information storage unit, comprising a memory, configured to store information indicating the trajectory.
 12. The endoscope system according to claim 10, wherein the processor is further configured to function as: a display condition setting unit configured to set a display condition of the trajectory and the indicator figure.
 13. A processor for the endoscope system according to claim 10, the processor comprising: the measurement unit; and the display control unit.
 14. The processor according to claim 13, wherein the processor is further configured to function as: an information acquisition unit configured to acquire information of the endoscope, wherein the display control unit determines whether measurement of the specific region by the displayed indicator figure is effective on the basis of the acquired information. 